1. Field of the Invention
The present invention relates to a display device.
2. Description of the Related Art
Display devices, including liquid crystal display devices and organic EL display devices, are widely used as display devices for information communication terminals, such as computers, and television sets. For example, the liquid crystal display device is a device using a liquid crystal display panel. The liquid crystal display panel displays an image by changing an electric field to change the alignment of a liquid crystal composition which is sealed between a thin film transistor (TFT) substrate and a counter substrate, thereby controlling the transmittance of light that passes through the two substrates and the liquid crystal composition. The electric field is changed for each of a plurality of pixels formed in the liquid crystal display panel.
In order to change the electric field for each pixel, the thin film transistor substrate of the liquid crystal display panel has a plurality of video signal lines and a plurality of scanning signal lines formed therein, and the video signal line and the scanning signal line are connected to a thin film transistor disposed in each pixel.
Then, to the video signal line, a video signal corresponding to a gray level of each pixel is output from a drain driver which is installed outside a display region of the liquid crystal display panel. To the scanning signal line, a signal (gate signal) indicative of a timing for inputting the video signal to each pixel is output from a gate driver which is installed outside the display region. The video signal supplied to each pixel is applied to a pixel electrode via the thin film transistor.
The above-mentioned drain driver and gate driver (herein, also referred to as drive circuits) are formed as, for example, a film package mounting a semiconductor chip, typified by chip on film (COF), and are connected to the thin film transistor substrate on which the video signal lines and the scanning signal lines are formed.
The thin film transistor substrate includes a terminal portion for making connection between the above-mentioned video signal lines or scanning signal lines and the above-mentioned COF. An example of this structure is disclosed in Japanese Patent Application Laid-open No. 2009-36871.